diff --git a/tests/libtest/lib556.c b/tests/libtest/lib556.c
index 22583a2365..85fd656998 100644
--- a/tests/libtest/lib556.c
+++ b/tests/libtest/lib556.c
@@ -54,7 +54,7 @@ int test(char *URL)
 
         total += iolen;
 
-      } while((res == CURLE_AGAIN) && (total < 129));
+      } while(((res == CURLE_OK) || (res == CURLE_AGAIN)) && (total < 129));
     }
   }